Nanomaterials

19 pages, 3162 KB

Open AccessEditor’s ChoiceArticle

A Multi-Method Approach to Analyzing MOFs for Chemical Warfare Simulant Capture: Molecular Simulation, Machine Learning, and Molecular Fingerprints

by Zhongyuan Ming, Min Zhang, Shouxin Zhang, Xiaopeng Li, Xiaoshan Yan, Kexin Guan, Yu Li, Yufeng Peng, Jinfeng Li, Heguo Li, Yue Zhao and Zhiwei Qiao

Nanomaterials 2025, 15(3), 183; https://doi.org/10.3390/nano15030183 - 24 Jan 2025

Cited by 2 | Viewed by 1934

Abstract

Mustard gas (HD) is a well-known chemical warfare agent, recognized for its extreme toxicity and severe hazards. Metal–organic frameworks (MOFs), with their unique structural properties, show significant potential for HD adsorption applications. Due to the extreme hazards of HD, most experimental studies focus [...] Read more.

Mustard gas (HD) is a well-known chemical warfare agent, recognized for its extreme toxicity and severe hazards. Metal–organic frameworks (MOFs), with their unique structural properties, show significant potential for HD adsorption applications. Due to the extreme hazards of HD, most experimental studies focus on its simulants, but molecular simulation research on these simulants remains limited. Simulation analyses of simulants can uncover structure–performance relationships and enable experimental validation, optimizing methods, and improving material design and performance predictions. This study integrates molecular simulations, machine learning (ML), and molecular fingerprinting (MFs) to identify MOFs with high adsorption performance for the HD simulant diethyl sulfide (DES), followed by in-depth structural analysis and comparison. First, MOFs are categorized into Top, Middle, and Bottom materials based on their adsorption efficiency. Univariate analysis, machine learning, and molecular fingerprinting are then used to identify and compare the distinguishing features and fingerprints of each category. Univariate analysis helps identify the optimal structural ranges of Top and Bottom materials, providing a reference for initial material screening. Machine learning feature importance analysis, combined with SHAP methods, identifies the key features that most significantly influence model predictions across categories, offering valuable insights for future material design. Molecular fingerprint analysis reveals critical fingerprint combinations, showing that adsorption performance is optimized when features such as metal oxides, nitrogen-containing heterocycles, six-membered rings, and C=C double bonds co-exist. The integrated analysis using HTCS, ML, and MFs provides new perspectives for designing high-performance MOFs and demonstrates significant potential for developing materials for the adsorption of CWAs and their simulants. Full article

(This article belongs to the Section Inorganic Materials and Metal-Organic Frameworks)

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25 pages, 2595 KB

Open AccessEditor’s ChoiceReview

The Role of Nanoparticles in Wine Science: Innovations and Applications

by Agnieszka Mierczynska-Vasilev

Nanomaterials 2025, 15(3), 175; https://doi.org/10.3390/nano15030175 - 23 Jan 2025

Cited by 1 | Viewed by 1910

Abstract

Viticulture, the science of growing, cultivating, and harvesting grapes, and enology, the art and science of making wine, are rapidly evolving through innovative approaches aimed at improving the quality and efficiency of grape and wine production. This review explores the emerging use of [...] Read more.

Viticulture, the science of growing, cultivating, and harvesting grapes, and enology, the art and science of making wine, are rapidly evolving through innovative approaches aimed at improving the quality and efficiency of grape and wine production. This review explores the emerging use of nanoparticles, in particular gold, silver, and magnetic nanoparticles, to improve the quality, safety, and sustainability of both grape growing and winemaking processes. The unique properties of these nanoparticles, such as their small size, high surface area, and distinct chemical properties, enable them to address key challenges within the industry. In viticulture, nanoparticles have shown potential in protecting vines from pathogens, optimizing grape yield, and improving quality. In enology, nanoparticles are making a significant contribution to microbial control, reducing spoilage and refining wine analysis techniques, leading to improved product quality and safety. This review also highlights the synergy between different types of nanoparticles and their diverse applications, from microbial control in wine production to their use in innovative packaging solutions. In addition, nanoparticles have the potential to reduce dependence on agrochemicals and improve the sustainability of wine production, which is a promising avenue for future research. However, the integration of nanoparticles in viticulture and enology also poses regulatory and safety challenges, including the potential for nanoparticles to leach into wine products. Further research and regulatory advances are essential to ensure the safe and effective use of these technologies in winemaking. Overall, nanoparticles offer significant benefits to the wine industry, driving improvements in efficiency, sustainability, and quality. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

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11 pages, 4983 KB

Open AccessEditor’s ChoiceArticle

Thin Hydrogenated Amorphous Silicon Carbide Layers with Embedded Ge Nanocrystals

by Zdeněk Remeš, Jiří Stuchlík, Jaroslav Kupčík and Oleg Babčenko

Nanomaterials 2025, 15(3), 176; https://doi.org/10.3390/nano15030176 - 23 Jan 2025

Cited by 2 | Viewed by 1341

Abstract

The in situ combination of plasma-enhanced chemical vapor deposition (PECVD) and vacuum evaporation in the same vacuum chamber allowed us to integrate germanium nanocrystals (Ge NCs) into hydrogenated amorphous silicon carbide (a-SiC:H) thin films deposited from monomethyl silane diluted with hydrogen. Transmission electron [...] Read more.

The in situ combination of plasma-enhanced chemical vapor deposition (PECVD) and vacuum evaporation in the same vacuum chamber allowed us to integrate germanium nanocrystals (Ge NCs) into hydrogenated amorphous silicon carbide (a-SiC:H) thin films deposited from monomethyl silane diluted with hydrogen. Transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX) spectroscopy were used for the microscopic characterization, while photothermal deflection spectroscopy (PDS) and near-infrared photoluminescence spectroscopy (NIR PL) were for optical characterization. The presence of Ge NCs embedded in the amorphous a-Si:C:H thin films was confirmed by TEM and EDX. The embedded Ge NCs increased optical absorption in the NIR spectral region. The quenching of a-SiC:H NIR PL due to the presence of Ge indicates that the diffusion length of free charge carriers in a-SiC:H is in the range of a few tens of nm, an order of magnitude less than in a-Si:H. The optical properties of a-SiC:H films were degraded after vacuum annealing at 550 °C. Full article

(This article belongs to the Section Nanocomposite Materials)

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15 pages, 3951 KB

Open AccessEditor’s ChoiceArticle

Mild Temperature Thermal Treatments of Gold-Exfoliated Monolayer MoS₂

by Emanuele Sangiorgi, Antonino Madonia, Gianmarco Laurella, Salvatore Ethan Panasci, Emanuela Schilirò, Filippo Giannazzo, Igor Píš, Federica Bondino, György Zoltán Radnóczi, Viktória Kovács-Kis, Béla Pécz, Gianpiero Buscarino, Franco Mario Gelardi, Marco Cannas and Simonpietro Agnello

Nanomaterials 2025, 15(3), 160; https://doi.org/10.3390/nano15030160 - 22 Jan 2025

Viewed by 1688

Abstract

Monolayer molybdenum disulfide is considered an extremely promising two-dimensional material for innovative electronics due to its direct bandgap and high charge-carrier mobility. The optical and electronic properties of monolayer MoS₂ can, however, be strongly influenced by the specific synthesis route, posing challenges [...] Read more.

Monolayer molybdenum disulfide is considered an extremely promising two-dimensional material for innovative electronics due to its direct bandgap and high charge-carrier mobility. The optical and electronic properties of monolayer MoS₂ can, however, be strongly influenced by the specific synthesis route, posing challenges for industrial-scale production. In this study, we investigated the effects of moderate temperature thermal treatments under a controlled O₂ atmosphere on the properties of monolayer MoS₂ flakes. We found that the treatments can effectively tune the doping level of monolayer MoS₂. Notably, 225 °C was identified as the optimal temperature for enhancing its optical emission properties. Our findings suggest that the removal of sulfur vacancies and impurities underlies these effects, demonstrating a promising approach for tuning the properties of monolayer MoS₂ at mild temperatures. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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53 pages, 9820 KB

Open AccessEditor’s ChoiceReview

Surface Functionalization of Nanocarriers with Anti-EGFR Ligands for Cancer Active Targeting

by Alessandra Spada and Sandrine Gerber-Lemaire

Nanomaterials 2025, 15(3), 158; https://doi.org/10.3390/nano15030158 - 21 Jan 2025

Cited by 15 | Viewed by 4258

Abstract

Active cancer targeting consists of the selective recognition of overexpressed biomarkers on cancer cell surfaces or within the tumor microenvironment, enabled by ligands conjugated to drug carriers. Nanoparticle (NP)-based systems are highly relevant for such an approach due to their large surface area [...] Read more.

Active cancer targeting consists of the selective recognition of overexpressed biomarkers on cancer cell surfaces or within the tumor microenvironment, enabled by ligands conjugated to drug carriers. Nanoparticle (NP)-based systems are highly relevant for such an approach due to their large surface area which is amenable to a variety of chemical modifications. Over the past decades, several studies have debated the efficiency of passive targeting, highlighting active targeting as a more specific and selective approach. The choice of conjugation chemistry for attaching ligands to nanocarriers is critical to ensure a stable and robust system. Among the panel of cancer biomarkers, the epidermal growth factor receptor (EGFR) stands as one of the most frequently overexpressed receptors in different cancer types. The design and development of nanocarriers with surface-bound anti-EGFR ligands are vital for targeted therapy, relying on their facilitated capture by EGFR-overexpressing tumor cells and enabling receptor-mediated endocytosis to improve drug accumulation within the tumor microenvironment. In this review, we examine several examples of the most recent and significant anti-EGFR nanocarriers and explore the various conjugation strategies for NP functionalization with anti-EGFR biomolecules and small molecular ligands. In addition, we also describe some of the most common characterization techniques to confirm and analyze the conjugation patterns. Full article

(This article belongs to the Special Issue The Future of Nanotechnology: Healthcare and Manufacturing)

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23 pages, 5469 KB

Open AccessEditor’s ChoiceArticle

Shutter-Synchronized Molecular Beam Epitaxy for Wafer-Scale Homogeneous GaAs and Telecom Wavelength Quantum Emitter Growth

by Elias Kersting, Hans-Georg Babin, Nikolai Spitzer, Jun-Yong Yan, Feng Liu, Andreas D. Wieck and Arne Ludwig

Nanomaterials 2025, 15(3), 157; https://doi.org/10.3390/nano15030157 - 21 Jan 2025

Viewed by 2055

Abstract

Quantum dot (QD)-based single-photon emitter devices today are based on self-assembled random position nucleated QDs emitting at random wavelengths. Deterministic QD growth in position and emitter wavelength would be highly appreciated for industry-scale high-yield device manufacturing from wafers. Local droplet etching during molecular [...] Read more.

Quantum dot (QD)-based single-photon emitter devices today are based on self-assembled random position nucleated QDs emitting at random wavelengths. Deterministic QD growth in position and emitter wavelength would be highly appreciated for industry-scale high-yield device manufacturing from wafers. Local droplet etching during molecular beam epitaxy is an all in situ method that allows excellent density control and predetermines the nucleation site of quantum dots. This method can produce strain-free GaAs QDs with excellent photonic and spin properties. Here, we focus on the emitter wavelength homogeneity. By wafer rotation-synchronized shutter opening time and adapted growth parameters, we grow QDs with a narrow peak emission wavelength homogeneity with no more than 1.2 nm shifts on a 45 mm diameter area and a narrow inhomogeneous ensemble broadening of only 2 nm at 4 K. The emission wavelength of these strain-free GaAs QDs is <800 nm, attractive for quantum optics experiments and quantum memory applications. We can use a similar random local droplet nucleation, nanohole drilling, and now, InAs infilling to produce QDs emitting in the telecommunication optical fiber transparency window around 1.3 µm, the so-called O-band. For this approach, we demonstrate good wavelength homogeneity and excellent density homogeneity beyond the possibilities of standard Stranski–Krastanov self-assembly. We discuss our methodology, structural and optical properties, and limitations set by our current setup capabilities. Full article

(This article belongs to the Section Nanophotonics Materials and Devices)

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16 pages, 6768 KB

Open AccessEditor’s ChoiceArticle

Mid-Infrared High-Power InGaAsSb/AlGaInAsSb Multiple-Quantum-Well Laser Diodes Around 2.9 μm

by Hongguang Yu, Chengao Yang, Yihang Chen, Jianmei Shi, Juntian Cao, Zhengqi Geng, Zhiyuan Wang, Haoran Wen, Enquan Zhang, Yu Zhang, Hao Tan, Donghai Wu, Yingqiang Xu, Haiqiao Ni and Zhichuan Niu

Nanomaterials 2025, 15(2), 139; https://doi.org/10.3390/nano15020139 - 17 Jan 2025

Viewed by 1330

Abstract

Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser’s performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. [...] Read more.

Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser’s performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser’s performance. The miscibility gap of the InGaAsSb alloy was systematically investigated by calculating the critical temperatures based on the delta lattice parameter model. As the calculation results show, In_0.54Ga_0.46As_0.23Sb_0.77, with a compressive strain of 1.74%, used as the quantum well, is out of the miscibility gap with no spinodal decomposition. The quantum wells exhibit high crystalline quality, as evidenced by distinct satellite peaks in XRD curves with a full width at half maximum (FWHM) of 56 arcseconds for the zeroth-order peak, a smooth surface with a root mean square (RMS) roughness of 0.19 nm, room-temperature photoluminescence with high luminous efficiency and narrow FHWM of 35 meV, and well-defined interfaces. These attributes effectively suppress non-radiative recombination, thereby enhancing internal quantum efficiency in the antimonide laser. Furthermore, a novel epitaxial laser structure was designed to acquire low optical absorption loss by decreasing the optical confinement factor in the cladding layer and implementing gradient doping in the p-type cladding layer. The continuous-wave output power of 310 mW was obtained at an injection current of 4.6 A and a heatsink temperature of 15 °C from a 1500 × 100 μm² single emitter. The external quantum efficiency of 53% was calculated with a slope efficiency of 0.226 W/A considering both of the uncoated facets. More importantly, the lasing wavelength of our laser exhibited a significant blue shift from 3.4 μm to 2.9 μm, which agrees with our calculated results when modeling the interdiffusion process in a quantum well. Therefore, the interdiffusion process must be considered for proper design and epitaxy to achieve mid-infrared high-power and high-efficiency antimonide laser diodes. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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13 pages, 5858 KB

Open AccessEditor’s ChoiceArticle

Temperature Sensing in Agarose/Silk Fibroin Translucent Hydrogels: Preparation of an Environment for Long-Term Observation

by Maria Micheva, Stanislav Baluschev and Katharina Landfester

Nanomaterials 2025, 15(2), 123; https://doi.org/10.3390/nano15020123 - 16 Jan 2025

Viewed by 3581

Abstract

Environmental changes, such as applied medication, nutrient depletion, and accumulation of metabolic residues, affect cell culture activity. The combination of these factors reflects on the local temperature distribution and local oxygen concentration towards the cell culture scaffold. However, determining the temporal variation of [...] Read more.

Environmental changes, such as applied medication, nutrient depletion, and accumulation of metabolic residues, affect cell culture activity. The combination of these factors reflects on the local temperature distribution and local oxygen concentration towards the cell culture scaffold. However, determining the temporal variation of local temperature, independent of local oxygen concentration changes in biological specimens, remains a significant technological challenge. The process of triplet–triplet annihilation upconversion (TTA-UC), performed in a nanoconfined environment with a continuous aqueous phase, appears to be a possible solution to these severe sensing problems. This process generates two optical signals (delayed emitter fluorescence (dF) and residual sensitizer phosphorescence (rPh)) in response to a single external stimulus (local temperature), allowing the application of the ratiometric-type sensing procedure. The ability to incorporate large amounts of sacrificial singlet oxygen scavenging materials, without altering the temperature sensitivity, allows long-term protection against photo-oxidative damage to the sensing moieties. Translucent agarose/silk fibroin hydrogels embedding non-ionic micellar systems containing energetically optimized annihilation couples simultaneously fulfill two critical functions: first, to serve as mechanical support (for further application as a cell culture scaffold); second, to allow tuning of the material response window to achieve a maximum temperature sensitivity better than 0.5 K for the physiologically important region around 36 °C. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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23 pages, 7326 KB

Open AccessEditor’s ChoiceArticle

Significance of Tool Coating Properties and Compacted Graphite Iron Microstructure for Tool Selection in Extreme Machining

by Anna Maria Esposito, Qianxi He, Jose M. DePaiva and Stephen C. Veldhuis

Nanomaterials 2025, 15(2), 130; https://doi.org/10.3390/nano15020130 - 16 Jan 2025

Viewed by 1256

Abstract

This study aims to determine the extent to which coating composition and workpiece properties impact machinability and tool selection when turning Compacted Graphite Iron (CGI) under extreme roughing conditions. Two CGI workpieces, differing in pearlite content and graphite nodularity, were machined at a [...] Read more.

This study aims to determine the extent to which coating composition and workpiece properties impact machinability and tool selection when turning Compacted Graphite Iron (CGI) under extreme roughing conditions. Two CGI workpieces, differing in pearlite content and graphite nodularity, were machined at a cutting speed of 180 m/min, feed rate of 0.18 mm/rev, and depth of cut of 3 mm. To assess the impact of tool properties across a wide range of commercially available tools, four diverse multilayered cemented carbide tools were evaluated: Tool A and Tool B with a thin AlTiSiN PVD coating, Tool C with a thick Al₂O₃-TiCN CVD coating, and Tool D with a thin Al₂O₃-TiC PVD coating. The machinability of CGI and wear mechanisms were analyzed using pre-cutting characterization, in-process optical microscopy, and post-test SEM analysis. The results revealed that CGI microstructural variations only affected tool life for Tool A, with a 110% increase in tool life between machining CGI Grade B and Grade A, but that the effects were negligible for all other tools. Tool C had a 250% and 70% longer tool life compared to the next best performance (Tool A) for CGI Grade A and CGI Grade B, respectively. With its thick CVD-coating, Tool C consistently outperformed the others due to its superior protection of the flank face and cutting edge under high-stress conditions. The cutting-induced stresses played a more significant role in the tool wear process than minor differences in workpiece microstructure or tool properties, and a thick CVD coating was most effective in addressing the tool wear effects for the extreme roughing conditions. However, differences in tool life for Tool A showed that tool behavior cannot be predicted based on a single system parameter, even for extreme conditions. Instead, tool properties, workpiece properties, cutting conditions, and their interactions should be considered collectively to evaluate the extent that an individual parameter impacts machinability. This research demonstrates that a comprehensive approach such as this can allow for more effective tool selection and thus lead to significant cost savings and more efficient manufacturing operations. Full article

(This article belongs to the Special Issue Mechanical Properties and Applications for Nanostructured Alloys)

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24 pages, 10552 KB

Open AccessEditor’s ChoiceReview

Nano-Oncologic Vaccine for Boosting Cancer Immunotherapy: The Horizons in Cancer Treatment

by Chao Chen, Yue Xu, Hui Meng, Hongyi Bao, Yong Hu, Chunjian Li and Donglin Xia

Nanomaterials 2025, 15(2), 122; https://doi.org/10.3390/nano15020122 - 16 Jan 2025

Cited by 3 | Viewed by 2807

Abstract

Nano-oncologic vaccines represent a groundbreaking approach in the field of cancer immunotherapy, leveraging the unique advantages of nanotechnology to enhance the effectiveness and specificity of cancer treatments. These vaccines utilize nanoscale carriers to deliver tumor-associated antigens and immunostimulatory adjuvants, facilitating targeted immune activation [...] Read more.

Nano-oncologic vaccines represent a groundbreaking approach in the field of cancer immunotherapy, leveraging the unique advantages of nanotechnology to enhance the effectiveness and specificity of cancer treatments. These vaccines utilize nanoscale carriers to deliver tumor-associated antigens and immunostimulatory adjuvants, facilitating targeted immune activation and promoting robust antitumor responses. By improving antigen presentation and localizing immune activation within the tumor microenvironment, nano-oncologic vaccines can significantly increase the efficacy of cancer immunotherapy, particularly when combined with other treatment modalities. This review highlights the mechanisms through which nano-oncologic vaccines operate, their potential to overcome existing limitations in cancer treatment, and ongoing advancements in design. Additionally, it discusses the targeted delivery approach, such as EPR effects, pH response, ultrasonic response, and magnetic response. The combination therapy effects with photothermal therapy, radiotherapy, or immune checkpoint inhibitors are also discussed. Overall, nano-oncologic vaccines hold great promise for changing the landscape of cancer treatment and advancing personalized medicine, paving the way for more effective therapeutic strategies tailored to individual patient needs. Full article

(This article belongs to the Special Issue Applications of Functional Nanomaterials in Biomedical Science)

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20 pages, 3827 KB

Open AccessFeature PaperEditor’s ChoiceReview

Two-Dimensional Ferroelectric Materials: From Prediction to Applications

by Shujuan Jiang, Yongwei Wang and Guangping Zheng

Nanomaterials 2025, 15(2), 109; https://doi.org/10.3390/nano15020109 - 12 Jan 2025

Cited by 1 | Viewed by 3229

Abstract

Ferroelectric materials hold immense potential for diverse applications in sensors, actuators, memory storage, and microelectronics. The discovery of two-dimensional (2D) ferroelectrics, particularly ultrathin compounds with stable crystal structure and room-temperature ferroelectricity, has led to significant advancements in the field. However, challenges such as [...] Read more.

Ferroelectric materials hold immense potential for diverse applications in sensors, actuators, memory storage, and microelectronics. The discovery of two-dimensional (2D) ferroelectrics, particularly ultrathin compounds with stable crystal structure and room-temperature ferroelectricity, has led to significant advancements in the field. However, challenges such as depolarization effects, low Curie temperature, and high energy barriers for polarization reversal remain in the development of 2D ferroelectrics with high performance. In this review, recent progress in the discovery and design of 2D ferroelectric materials is discussed, focusing on their properties, underlying mechanisms, and applications. Based on the work discussed in this review, we look ahead to theoretical prediction for 2D ferroelectric materials and their potential applications, such as the application in nonlinear optics. The progress in theoretical and experimental research could lead to the discovery and design of next-generation nanoelectronic and optoelectronic devices, facilitating the applications of 2D ferroelectric materials in emerging advanced technologies. Full article

(This article belongs to the Special Issue Design of Nanomaterials by Computer Simulation and Artificial Intelligence Approaches (2nd Edition))

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15 pages, 2985 KB

Open AccessEditor’s ChoiceArticle

‘Ship-in-a-Bottle’ Integration of pH-Sensitive 3D Proteinaceous Meshes into Microfluidic Channels

by Daniela Serien, Koji Sugioka and Aiko Narazaki

Nanomaterials 2025, 15(2), 104; https://doi.org/10.3390/nano15020104 - 10 Jan 2025

Cited by 1 | Viewed by 1162

Abstract

Microfluidic sensors incorporated onto chips allow sensor miniaturization and high-throughput analyses for point-of-care or non-clinical analytical tools. Three-dimensional (3D) printing based on femtosecond laser direct writing (fs-LDW) is useful for creating 3D microstructures with high spatial resolution because the structures are printed in [...] Read more.

Microfluidic sensors incorporated onto chips allow sensor miniaturization and high-throughput analyses for point-of-care or non-clinical analytical tools. Three-dimensional (3D) printing based on femtosecond laser direct writing (fs-LDW) is useful for creating 3D microstructures with high spatial resolution because the structures are printed in 3D space along a designated laser light path. High-performance biochips can be fabricated using the ‘ship-in-a-bottle’ integration technique, in which functional microcomponents or biomimetic structures are embedded inside closed microchannels using fs-LDW. Solutions containing protein biomacromolecules as a precursor can be used to fabricate microstructures that retain their native protein functions. Here, we demonstrate the ship-in-a-bottle integration of pure 3D proteinaceous microstructures that exhibit pH sensitivity. We fabricated proteinaceous mesh structures with gap sizes of 10 and 5 μm. The sizes of these gaps changed when exposed to physiological buffers ranging from pH of 4 to 10. The size of the gaps in the mesh can be shrunk and expanded repeatedly by changing the pH of the surrounding buffer. Fs-LDW enables the construction of microscopic proteinaceous meshes that exhibit dynamic functions such as pH sensing and might find applications for filtering particles in microfluidic channels. Full article

(This article belongs to the Section Nanofabrication and Nanomanufacturing)

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18 pages, 5127 KB

Open AccessEditor’s ChoiceArticle

Green Synthesis of Copper Nanoparticles from the Aqueous Extract of Lonicera japonica Thunb and Evaluation of Its Catalytic Property and Cytotoxicity and Antimicrobial Activity

by Weijie Yu, Jingyi Tang, Chunxia Gao, Xuesong Zheng and Peizhi Zhu

Nanomaterials 2025, 15(2), 91; https://doi.org/10.3390/nano15020091 - 9 Jan 2025

Cited by 6 | Viewed by 2543

Abstract

In this study, copper nanoparticles with an average particle size of 2–4 nm were synthesized using the green extract of Lonicera japonica Thunb. The catalytic activity and dye degradation efficiency of Cu NPs were evaluated using ultraviolet spectroscopy. To confirm that Cu NPs [...] Read more.

In this study, copper nanoparticles with an average particle size of 2–4 nm were synthesized using the green extract of Lonicera japonica Thunb. The catalytic activity and dye degradation efficiency of Cu NPs were evaluated using ultraviolet spectroscopy. To confirm that Cu NPs can continuously remove organic dyes, this study used Cu/Lj-C composite material adsorbed on cotton balls as a simulated bed to study the cyclic catalytic activity of Cu NPs for the reduction of methylene blue by sodium borohydride (NaBH₄). The experiment showed that after multiple cycles, it can also quickly and effectively reduce methylene blue. To evaluate the toxicity of Cu NPs, experiments were conducted using HUVEC and MC3T3-E1 cells. The median lethal doses (LD₅₀) were 37.64 µg/mL and 7.50 µg/mL. The synthesized Cu NPs also exhibited antibacterial efficacy against Aspergillus niger (fungus), Staphylococcus aureus (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria), and Candida albicans (yeast). Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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17 pages, 7747 KB

Open AccessEditor’s ChoiceArticle

Calcium Phosphate Nanoparticles Functionalized with a Cardio-Specific Peptide

by Federica Mancini, Lorenzo Degli Esposti, Alessio Adamiano, Jessica Modica, Daniele Catalucci, Dora Mehn, Otmar Geiss and Michele Iafisco

Nanomaterials 2025, 15(2), 94; https://doi.org/10.3390/nano15020094 - 9 Jan 2025

Viewed by 1656

Abstract

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, highliting the urgent need for new therapeutic strategies. Peptide-based therapies have demonstrated significant potential for treating CVDs; however, their clinical application is hindered by their limited stability in physiological fluids. To overcome this [...] Read more.

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, highliting the urgent need for new therapeutic strategies. Peptide-based therapies have demonstrated significant potential for treating CVDs; however, their clinical application is hindered by their limited stability in physiological fluids. To overcome this challenge, an effective drug delivery system is essential to protect and efficiently transport peptides to their intended targets. This study introduces two distinct strategies for loading a cardio-specific mimetic peptide (MP), previously designed to modulate L-type calcium channel function in cardiomyocytes, onto calcium phosphate nanoparticles (CaP NPs). MP-loaded CaP NPs were prepared by two different wet precipitation syntheses, one of which involved the use of sodium polyacrylate as a templating agent. Characterization of MP-loaded CaP NPs showed that their crystallinity, size, surface charge, and morphology could be tuned by adjusting the synthesis parameters. In vitro tests on cardiac cells confirmed that both types of MP-loaded CaP NPs are biocompatible with HL-1 cardiomyocytes and restored intracellular calcium flux under stressed conditions, highlighting their therapeutic potential. These results pave the way for further optimization of CaP NP formulations and suggest their potential as a viable nanomaterial for CVD treatment. Full article

(This article belongs to the Special Issue Applications of Calcium Phosphate-Based Nanostructured Materials and Coatings: 2nd Edition)

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15 pages, 8790 KB

Open AccessEditor’s ChoiceArticle

A Graphene/MXene-Modified Flexible Fabric for Infrared Camouflage, Electrothermal, and Electromagnetic Interference Shielding

by Xianguang Hou, Ziyi Zang, Yaxin Meng, Tian Wang, Shuai Gao, Qingman Liu, Lijun Qu and Xiansheng Zhang

Nanomaterials 2025, 15(2), 98; https://doi.org/10.3390/nano15020098 - 9 Jan 2025

Cited by 4 | Viewed by 2780

Abstract

Although materials with infrared camouflage capabilities are increasingly being produced, few applications exist in clothing fabrics. Here, graphene/MXene-modified fabric with superior infrared camouflage, Joule heating, and electromagnetic shielding capabilities all in one was prepared by simply scraping a graphene slurry onto alkali-treated cotton [...] Read more.

Although materials with infrared camouflage capabilities are increasingly being produced, few applications exist in clothing fabrics. Here, graphene/MXene-modified fabric with superior infrared camouflage, Joule heating, and electromagnetic shielding capabilities all in one was prepared by simply scraping a graphene slurry onto alkali-treated cotton fabrics, followed by spraying MXene. The functionality of the modified fabrics after different treatment times was then tested and analyzed. The results indicate that the mid-infrared emissivity of the modified fabric decreases with an increase in the coating times of graphene and MXene. When the graphene/MXene-modified fabrics are prepared at loads of 5 and 1.2 mg/cm², respectively, the modified fabrics have very low infrared emissivity in the 3–5 and 8–14 μm bands, and the surface temperature can be reduced by 53.1 °C when placed on a heater with a temperature of 100 °C (surface radiation temperature of 95 °C). The modified fabric also demonstrates excellent Joule heating capabilities; at 4 V of power, a temperature of 91.7 °C may be reached in 30 s. In addition, customized materials exhibit strong electromagnetic shielding performance. By simply folding the cloth, the electromagnetic interference shield effect can be increased to 64.3 dB. With their superior infrared camouflage, thermal management, and electromagnetic shielding performance, graphene/MXene-modified fabrics have found extensive use in intelligent wearables and military applications. Full article

(This article belongs to the Section 2D and Carbon Nanomaterials)

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31 pages, 8883 KB

Open AccessEditor’s ChoiceReview

Research on Red/Near-Infrared Fluorescent Carbon Dots Based on Different Carbon Sources and Solvents: Fluorescence Mechanism and Biological Applications

by Jun Song, Minghao Kang, Shujian Ji, Shuai Ye and Jiaqing Guo

Nanomaterials 2025, 15(2), 81; https://doi.org/10.3390/nano15020081 - 7 Jan 2025

Cited by 4 | Viewed by 2423

Abstract

Fluorescent carbon dots, especially red/near-infrared-emitting CDs, are becoming increasingly important in the field of biomedicine. This article reviews the synthesis, fluorescence mechanisms, and biological applications of R/NIR-CDs, emphasizing the importance of carbon source and solvent selection in controlling their optical properties. The formation [...] Read more.

Fluorescent carbon dots, especially red/near-infrared-emitting CDs, are becoming increasingly important in the field of biomedicine. This article reviews the synthesis, fluorescence mechanisms, and biological applications of R/NIR-CDs, emphasizing the importance of carbon source and solvent selection in controlling their optical properties. The formation process of CDs is classified, and the fluorescence mechanisms of CDs are summarized, involving carbon core states, surface states, molecular states, and cross-linking enhanced emission effects. This article also highlights the applications of R/NIR-CDs in bioimaging, biosensing, phototherapy, and drug delivery. The final section discusses challenges and prospects. Full article

(This article belongs to the Section Nanophotonics Materials and Devices)

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20 pages, 3114 KB

Open AccessEditor’s ChoiceArticle

Tin(IV)Porphyrin-Based Porous Coordination Polymers as Efficient Visible Light Photocatalyst for Wastewater Remediation

by Nirmal Kumar Shee and Hee-Joon Kim

Nanomaterials 2025, 15(1), 59; https://doi.org/10.3390/nano15010059 - 2 Jan 2025

Viewed by 1576

Abstract

Two porphyrin-based polymeric frameworks, SnP-BTC and SnP-BTB, as visible light photocatalysts for wastewater remediation were prepared by the solvothermal reaction of trans-dihydroxo-[5,15,10,20-tetrakis(phenyl)porphyrinato]tin(IV) (SnP) with 1,3,5-benzenetricarboxylic acid (H₃BTC) and 1,3,5-tris(4-carboxyphenyl)benzene (H₃BTB), respectively. The strong bond between the carboxylic acid [...] Read more.

Two porphyrin-based polymeric frameworks, SnP-BTC and SnP-BTB, as visible light photocatalysts for wastewater remediation were prepared by the solvothermal reaction of trans-dihydroxo-[5,15,10,20-tetrakis(phenyl)porphyrinato]tin(IV) (SnP) with 1,3,5-benzenetricarboxylic acid (H₃BTC) and 1,3,5-tris(4-carboxyphenyl)benzene (H₃BTB), respectively. The strong bond between the carboxylic acid group of H₃BTC and H₃BTB with the axial hydroxyl moiety of SnP leads to the formation of highly stable polymeric architectures. Incorporating the carboxylic acid group onto the surface of SnP changes the conformational frameworks as well as produces rigid structural transformation that includes permanent porosity, good thermodynamic stability, interesting morphology, and excellent photocatalytic degradation activity against AM dye and TC antibiotic under visible light irradiation. The photocatalytic degradation activities of AM dye were found to be 95% by SnP-BTB and 87% by SnP-BTC within 80 min. Within 60 min of visible light exposure, the photocatalytic degradation activities of TC antibiotic were found to be 70% by SnP-BTB and 60% by SnP-BTC. The enhanced catalytic photodegradation performances of SnP-BTB and SnP-BTC were attributed to the synergistic effect between SnP and carboxylic acid groups. The carboxylic acid connectors strongly resist the separation of SnP from the surface of SnP-BTB and SnP-BTC during the photodegradation experiments. Therefore, the high degradation rate and low catalyst loading make SnP-BTB or SnP-BTC more efficient than other reported catalysts. Thus, the present investigations on the porphyrin-based photocatalysts hold great promise in tackling the treatment of dyeing wastewater. Full article

(This article belongs to the Special Issue Environmental Restoration Materials and Technologies)

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19 pages, 10251 KB

Open AccessEditor’s ChoiceArticle

Nanosized κ-Carbide and B2 Boosting Strength Without Sacrificing Ductility in a Low-Density Fe-32Mn-11Al Steel

by Changwei He, Yongfeng Shen, Wenying Xue, Zhijian Fan and Yiran Zhou

Nanomaterials 2025, 15(1), 48; https://doi.org/10.3390/nano15010048 - 30 Dec 2024

Cited by 11 | Viewed by 1275

Abstract

High-performance lightweight materials are urgently needed because of energy savings and emission reduction. Here, we design a new steel with a low density of 6.41 g/cm³, which is a 20% weight reduction compared to the conventional steel. The mechanical properties and [...] Read more.

High-performance lightweight materials are urgently needed because of energy savings and emission reduction. Here, we design a new steel with a low density of 6.41 g/cm³, which is a 20% weight reduction compared to the conventional steel. The mechanical properties and microstructures of the steels prepared with different routes are systematically explored by utilizing uniaxial tensile testing and transmission electron microscopy. The steel processed by cold rolling and recrystallization annealing at 950 °C for 15 min shows an ultra-high yield strength of 1241 ± 10 MPa, while retaining a good ductility of 38 ± 1%. The high yield strength is mainly related to the synergistic precipitation strengthening introduced by nanoscale B2 and κ′-carbides. It is encouraging to notice that the yield strength increased without scarifying ductility, compared to the ST steel. The key reason is that the high strain hardening rate is activated by combined factors, including the blockage of numerous twins and nanoscale B2 to the dislocation movements, and dynamic slip band refinement. This study is instructive for concurrently enhancing the strength and ductility of austenitic lightweight steels with fully recrystallized grains and dual nano-precipitates. Full article

(This article belongs to the Section 2D and Carbon Nanomaterials)

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13 pages, 3997 KB

Open AccessEditor’s ChoiceArticle

Reliable Atom Probe Tomography of Cu Nanoparticles Through Tailored Encapsulation by an Electrodeposited Film

by Aydan Çiçek, Florian Knabl, Maximilian Schiester, Helene Waldl, Lidija D. Rafailović, Michael Tkadletz and Christian Mitterer

Nanomaterials 2025, 15(1), 43; https://doi.org/10.3390/nano15010043 - 30 Dec 2024

Viewed by 1308

Abstract

Nanoparticles are essential for energy storage, catalysis, and medical applications, emphasizing their accurate chemical characterization. However, atom probe tomography (APT) of nanoparticles sandwiched at the interface between an encapsulating film and a substrate poses difficulties. Poor adhesion at the film-substrate interface can cause [...] Read more.

Nanoparticles are essential for energy storage, catalysis, and medical applications, emphasizing their accurate chemical characterization. However, atom probe tomography (APT) of nanoparticles sandwiched at the interface between an encapsulating film and a substrate poses difficulties. Poor adhesion at the film-substrate interface can cause specimen fracture during APT, while impurities may introduce additional peaks in the mass spectra. We demonstrate preparing APT specimens with strong adhesion between nanoparticles and film/substrate matrices for successful analysis. Copper nanoparticles were encapsulated at the interface between nickel film and cobalt substrate using electrodeposition. Cobalt and nickel were chosen to match their evaporation fields with copper, minimizing peak overlaps and aiding nanoparticle localization. Copper nanoparticles were deposited via magnetron sputter inert gas condensation with varying deposition times to yield suitable surface coverages, followed by encapsulation with the nickel film. In-plane and cross-plane APT specimens were prepared by femtosecond laser ablation and focused ion beam milling. Longer deposition times resulted in agglomerated nanoparticles as well as pores and voids, causing poor adhesion and specimen failure. In contrast, shorter deposition times provided sufficient surface coverage, ensuring strong adhesion and reducing void formation. This study emphasizes controlled surface coverage for reliable APT analysis, offering insights into nanoparticle chemistry. Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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21 pages, 5129 KB

Open AccessEditor’s ChoiceArticle

Peroxidase (POD) Mimicking Activity of Different Types of Poly(ethyleneimine)-Mediated Prussian Blue Nanoparticles

by Udara Bimendra Gunatilake, Briza Pérez-López, Maria Urpi, Judit Prat-Trunas, Gerard Carrera-Cardona, Gautier Félix, Saad Sene, Mickaël Beaudhuin, Jean-Charles Dupin, Joachim Allouche, Yannick Guari, Joulia Larionova and Eva Baldrich

Nanomaterials 2025, 15(1), 41; https://doi.org/10.3390/nano15010041 - 29 Dec 2024

Cited by 2 | Viewed by 2236

Abstract

Prussian blue nanoparticles (PBNPs) have been identified as a promising candidate for biomimetic peroxidase (POD)-like activity, specifically due to the metal centres (Fe³⁺/Fe²⁺) of Prussian blue (PB), which have the potential to function as catalytically active centres. The decoration [...] Read more.

Prussian blue nanoparticles (PBNPs) have been identified as a promising candidate for biomimetic peroxidase (POD)-like activity, specifically due to the metal centres (Fe³⁺/Fe²⁺) of Prussian blue (PB), which have the potential to function as catalytically active centres. The decoration of PBNPs with desired functional polymers (such as amino- or carboxylate-based) primarily facilitates the subsequent linkage of biomolecules to the nanoparticles for their use in biosensor applications. Thus, the elucidation of the catalytic POD mimicry of these systems is of significant scientific interest but has not been investigated in depth yet. In this report, we studied a series of poly(ethyleneimine) (PEI)-mediated PBNPs (PB/PEI NPs) prepared using various synthesis protocols. The resulting range of particles with varying size (~19–92 nm) and shape combinations were characterised in order to gain insights into their physicochemical properties. The POD-like nanozyme activity of these nanoparticles was then investigated by utilising a 3,3′,5,5′-tetramethylbenzidine (TMB)/H₂O₂ system, with the catalytic performance of the natural enzyme horseradish peroxidase (HRP) serving as a point of comparison. It was shown that most PB/PEI NPs displayed higher catalytic activity than the PBNPs, with higher activity observed in particles of smaller size, higher Fe content, and higher Fe²⁺/Fe³⁺ ratio. Furthermore, the nanoparticles demonstrated enhanced chemical stability in the presence of acid, sodium azide, or high concentrations of H₂O₂ when compared to HRP, confirming the viability of PB/PEI NPs as a promising nanozymatic material. This study disseminates fundamental knowledge on PB/PEI NPs and their POD-like activities, which will facilitate the selection of an appropriate particle type for future biosensor applications. Full article

(This article belongs to the Special Issue Advanced Porous Nanomaterials: Synthesis, Properties, and Application (Second Edition))

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16 pages, 2893 KB

Open AccessEditor’s ChoiceArticle

Cryo-SIMPLY: A Reliable STT-MRAM-Based Smart Material Implication Architecture for In-Memory Computing

by Tatiana Moposita, Esteban Garzón, Adam Teman and Marco Lanuzza

Nanomaterials 2025, 15(1), 9; https://doi.org/10.3390/nano15010009 - 25 Dec 2024

Cited by 1 | Viewed by 1659

Abstract

This paper presents Cryo-SIMPLY, a reliable smart material implication (SIMPLY) operating at cryogenic conditions (77 K). The assessment considers SIMPLY schemes based on spin-transfer torque magnetic random access memory (STT-MRAM) technology with single-barrier magnetic tunnel junction (SMTJ) and double-barrier magnetic tunnel junction (DMTJ). [...] Read more.

This paper presents Cryo-SIMPLY, a reliable smart material implication (SIMPLY) operating at cryogenic conditions (77 K). The assessment considers SIMPLY schemes based on spin-transfer torque magnetic random access memory (STT-MRAM) technology with single-barrier magnetic tunnel junction (SMTJ) and double-barrier magnetic tunnel junction (DMTJ). Our study relies on a temperature-aware macrospin-based Verilog-A compact model for MTJ devices and a 65 nm commercial process design kit (PDK) calibrated down to 77 K under silicon measurements. The DMTJ-based SIMPLY demonstrates a significant improvement in read margin at 77 K, overcoming the conventional SIMPLY scheme at room temperature (300 K) by approximately 2.3 X. When implementing logic operations with the SIMPLY scheme operating at 77 K, the DMTJ-based scheme assures energy savings of about 69%, as compared to its SMTJ-based counterpart operating at 77 K. Overall, our results prove that the SIMPLY scheme at cryogenic conditions is a promising solution for reliable and energy-efficient logic-in-memory (LIM) architectures. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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21 pages, 3805 KB

Open AccessEditor’s ChoiceArticle

Embedment of Biosynthesised Silver Nanoparticles in PolyNIPAAm/Chitosan Hydrogel for Development of Proactive Smart Textiles

by Dominika Glažar, Danaja Štular, Ivan Jerman, Barbara Simončič and Brigita Tomšič

Nanomaterials 2025, 15(1), 10; https://doi.org/10.3390/nano15010010 - 25 Dec 2024

Cited by 2 | Viewed by 1330

Abstract

A smart viscose fabric with temperature and pH responsiveness and proactive antibacterial and UV protection was developed. PNCS (poly-(N-isopropylakrylamide)/chitosan) hydrogel was used as the carrier of silver nanoparticles (Ag NPs), synthesised in an environmentally friendly manner using AgNO₃ and a sumac leaf [...] Read more.

A smart viscose fabric with temperature and pH responsiveness and proactive antibacterial and UV protection was developed. PNCS (poly-(N-isopropylakrylamide)/chitosan) hydrogel was used as the carrier of silver nanoparticles (Ag NPs), synthesised in an environmentally friendly manner using AgNO₃ and a sumac leaf extract. PNCS hydrogel and Ag NPs were applied to the viscose fabric by either in situ synthesis of Ag NPs on the surface of viscose fibres previously modified with PNCS hydrogel, or by the direct immobilisation of Ag NPs by the dehydration/hydration of the PNCS hydrogel with the nanodispersion of Ag NPs in the sumac leaf extract and subsequent application to the viscose fibres. Compared to the pre-functionalised PNCS application method, the in situ functionalisation imparted much higher concentration of Ag NPs on the fibres, colouring the samples brown to brown-green. These samples showed more than 90% reduction in the test bacteria E. coli and S. aureus and provided excellent UV protection. In this case, the PNCS hydrogel acted as a reservoir for Ag NPs, whose release was based on a diffusion-controlled mechanism. Despite the Ag NPs decreasing the responsiveness of the PNCS hydrogel, the moisture management was still preserved in the modified samples. Accordingly, the PNCS hydrogel is a suitable carrier for biosynthesized Ag NPs to tailor the protective smart surface of viscose fibres. Full article

(This article belongs to the Special Issue Antimicrobial and Antioxidant Activity of Nanoparticles)

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22 pages, 11586 KB

Open AccessEditor’s ChoiceReview

New Strategy for Microbial Corrosion Protection: Photocatalytic Antimicrobial Quantum Dots

by Shijia Liu, Dapeng Wu, Jie Zheng, Baochen Han, Jian Qi, Fanchun Meng, Jianhui Li and Dan Liu

Nanomaterials 2025, 15(1), 2; https://doi.org/10.3390/nano15010002 - 24 Dec 2024

Viewed by 1691

Abstract

Microbial corrosion has significant implications for the economy, environment, and human safety worldwide. Photocatalytic antibacterial technology, owing to its advantages in environmental protection, broad-spectrum, and efficient sterilization, presents a compelling alternative to traditional antibacterial strategies for microbial corrosion protection. In recent years, photocatalytic [...] Read more.

Microbial corrosion has significant implications for the economy, environment, and human safety worldwide. Photocatalytic antibacterial technology, owing to its advantages in environmental protection, broad-spectrum, and efficient sterilization, presents a compelling alternative to traditional antibacterial strategies for microbial corrosion protection. In recent years, photocatalytic quantum dot materials have garnered considerable attention in this field due to their unique quantum effects. This article provides a brief overview of the quantum effects associated with quantum dot materials, reviews the classification and preparation methods of these photocatalytic quantum dots, and elucidates their inhibitory effects and mechanisms against microbial corrosion. Finally, this article summarizes unresolved issues and prospects for the future development of quantum dots in the realm of microbial corrosion protection. Full article

(This article belongs to the Special Issue Anticorrosive Nanomaterials and Nanostructured Coatings)

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19 pages, 3781 KB

Open AccessEditor’s ChoiceArticle

Constructing Dynamical Symmetries for Quantum Computing: Applications to Coherent Dynamics in Coupled Quantum Dots

by James R. Hamilton, Raphael D. Levine and Francoise Remacle

Nanomaterials 2024, 14(24), 2056; https://doi.org/10.3390/nano14242056 - 23 Dec 2024

Cited by 2 | Viewed by 998

Abstract

Dynamical symmetries, time-dependent operators that almost commute with the Hamiltonian, extend the role of ordinary symmetries. Motivated by progress in quantum technologies, we illustrate a practical algebraic approach to computing such time-dependent operators. Explicitly we expand them as a linear combination of time-independent [...] Read more.

Dynamical symmetries, time-dependent operators that almost commute with the Hamiltonian, extend the role of ordinary symmetries. Motivated by progress in quantum technologies, we illustrate a practical algebraic approach to computing such time-dependent operators. Explicitly we expand them as a linear combination of time-independent operators with time-dependent coefficients. There are possible applications to the dynamics of systems of coupled coherent two-state systems, such as qubits, pumped by optical excitation and other addressing inputs. Thereby, the interaction of the system with the excitation is bilinear in the coherence between the two states and in the strength of the time-dependent excitation. The total Hamiltonian is a sum of such bilinear terms and of terms linear in the populations. The terms in the Hamiltonian form a basis for Lie algebra, which can be represented as coupled individual two-state systems, each using the population and the coherence between two states. Using the factorization approach of Wei and Norman, we construct a unitary quantum mechanical evolution operator that is a factored contribution of individual two-state systems. By that one can accurately propagate both the wave function and the density matrix with special relevance to quantum computing based on qubit architecture. Explicit examples are derived for the electronic dynamics in coupled semi-conducting nanoparticles that can be used as hardware for quantum technologies. Full article

(This article belongs to the Special Issue Quantum Computing and Nanomaterial Simulations)

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15 pages, 8375 KB

Open AccessEditor’s ChoiceArticle

Nanodots of Transition Metal Sulfides, Carbonates, and Oxides Obtained Through Spontaneous Co-Precipitation with Silica

by Bastian Rödig, Diana Funkner, Thomas Frank, Ulrich Schürmann, Julian Rieder, Lorenz Kienle, Werner Kunz and Matthias Kellermeier

Nanomaterials 2024, 14(24), 2054; https://doi.org/10.3390/nano14242054 - 23 Dec 2024

Viewed by 1766

Abstract

The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and [...] Read more.

The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and require non-aqueous media and/or high temperatures, all of which appear critical with respect to production costs, safety, and sustainability. In the present work, we demonstrate a simple one-pot process in water under ambient conditions that can produce particles of various transition metal carbonates and sulfides with sizes of only a few nanometers embedded in a silica shell, similar to particles derived from more elaborate synthesis routes, like the sol–gel process. To this end, solutions of soluble salts of metal cations (e.g., chlorides) and the respective anions (e.g., sodium carbonate or sulfide) are mixed in the presence of different amounts of sodium silicate at elevated pH levels. Upon mixing, metal carbonate/sulfide particles nucleate, and their subsequent growth causes a sensible decrease of pH in the vicinity. Dissolved silicate species respond to this local acidification by condensation reactions, which eventually lead to the formation of amorphous silica layers that encapsulate the metal carbonate/sulfide cores and, thus, effectively inhibit any further growth. The as-obtained carbonate nanodots can readily be converted into the corresponding metal oxides by secondary thermal treatment, during which their nanometric size is maintained. Although the described method clearly requires optimization towards actual applications, the results of this study highlight the potential of bottom-up self-assembly for the synthesis of functional nanoparticles at mild conditions. Full article

(This article belongs to the Section Inorganic Materials and Metal-Organic Frameworks)

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13 pages, 3253 KB

Open AccessEditor’s ChoiceArticle

Effects of Au Addition on the Performance of Thermal Electronic Noses Based on Porous Cu₂O–SnO₂ Nanospheres

by Matteo Tonezzer, Taro Ueda, Soichiro Torai, Koki Fujita, Yasuhiro Shimizu and Takeo Hyodo

Nanomaterials 2024, 14(24), 2052; https://doi.org/10.3390/nano14242052 - 22 Dec 2024

Viewed by 1002

Abstract

The electronic nose is an increasingly useful tool in many fields and applications. Our thermal electronic nose approach, based on nanostructured metal oxide chemiresistors in a thermal gradient, has the advantage of being tiny and therefore integrable in portable and wearable devices. Obviously, [...] Read more.

The electronic nose is an increasingly useful tool in many fields and applications. Our thermal electronic nose approach, based on nanostructured metal oxide chemiresistors in a thermal gradient, has the advantage of being tiny and therefore integrable in portable and wearable devices. Obviously, a wise choice of the nanomaterial is crucial for the device’s performance and should therefore be carefully considered. Here we show how the addition of different amounts of Au (between 1 and 5 wt%) on Cu₂O–SnO₂ nanospheres affects the thermal electronic nose performance. Interestingly, the best performance is not achieved with the material offering the highest intrinsic selectivity. This confirms the importance of specific studies, since the performance of chemoresistive gas sensors does not linearly affect the performance of the electronic nose. By optimizing the amount of Au, the device achieved a perfect classification of the tested gases (acetone, ethanol, and toluene) and a good concentration estimation (with a mean absolute percentage error around 16%). These performances, combined with potentially smaller dimensions of less than 0.5 mm², make this thermal electronic nose an ideal candidate for numerous applications, such as in the agri-food, environmental, and biomedical sectors. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

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36 pages, 8819 KB

Open AccessEditor’s ChoiceReview

Harnessing Radiation for Nanotechnology: A Comprehensive Review of Techniques, Innovations, and Application

by Mobinul Islam, Md. Shahriar Ahmed, Sua Yun, Hae-Yong Kim and Kyung-Wan Nam

Nanomaterials 2024, 14(24), 2051; https://doi.org/10.3390/nano14242051 - 21 Dec 2024

Cited by 2 | Viewed by 3239

Abstract

Nanomaterial properties such as size, structure, and composition can be controlled by manipulating radiation, such as gamma rays, X-rays, and electron beams. This control allows scientists to create materials with desired properties that can be used in a wide range of applications, from [...] Read more.

Nanomaterial properties such as size, structure, and composition can be controlled by manipulating radiation, such as gamma rays, X-rays, and electron beams. This control allows scientists to create materials with desired properties that can be used in a wide range of applications, from electronics to medicine. This use of radiation for nanotechnology is revolutionizing the way we design and manufacture materials. Additionally, radiation-induced nanomaterials are more cost effective and energy efficient. This technology is also having a positive impact on the environment, as materials are being produced with fewer emissions, less energy, and less waste. This cutting-edge technology is opening up new possibilities and has become an attractive option for many industries, from medical advancements to energy storage. It is also helping to make the world a better place by reducing our carbon footprint and preserving natural resources. This review aims to meticulously point out the synthesis approach and highlights significant progress in generating radiation-induced nanomaterials with tunable and complex morphologies. This comprehensive review article is essential for researchers to design innovative materials for advancements in health care, electronics, energy storage, and environmental remediation. Full article

(This article belongs to the Special Issue Radiation Technology in Nanomaterials)

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17 pages, 4113 KB

Open AccessEditor’s ChoiceReview

Electron Holography for Advanced Characterization of Permanent Magnets: Demagnetization Field Mapping and Enhanced Precision in Phase Analysis

by Sujin Lee

Nanomaterials 2024, 14(24), 2046; https://doi.org/10.3390/nano14242046 - 20 Dec 2024

Viewed by 1753

Abstract

This review explores a method of visualizing a demagnetization field (H_d) within a thin-foiled Nd₂Fe₁₄B specimen using electron holography observation. Mapping the H_d is critical in electron holography as it provides the only information on [...] Read more.

This review explores a method of visualizing a demagnetization field (H_d) within a thin-foiled Nd₂Fe₁₄B specimen using electron holography observation. Mapping the H_d is critical in electron holography as it provides the only information on magnetic flux density. The H_d map within a Nd₂Fe₁₄B thin foil, derived from this method, showed good agreement with the micromagnetic simulation result, providing valuable insights related to coercivity. Furthermore, this review examines the application of the wavelet hidden Markov model (WHMM) for noise suppression in thin-foiled Nd₂Fe₁₄B crystals. The results show significant suppression of artificial phase jumps in the reconstructed phase images due to the poor visibility of electron holograms under the narrowest fringe spacing required for spatial resolution in electron holography. These techniques substantially enhance the precision of phase analysis and are applicable to a wide range of magnetic materials, enabling more accurate magnetic characterization. Full article

(This article belongs to the Special Issue Exploring Nanomaterials through Electron Microscopy and Spectroscopy)

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14 pages, 12358 KB

Open AccessEditor’s ChoiceArticle

Oxygenated VOC Detection Using SnO₂ Nanoparticles with Uniformly Dispersed Bi₂O₃

by Haoyue Yang, Koichi Suematsu, Felipe Hiroshi Mashiba, Ken Watanabe and Kengo Shimanoe

Nanomaterials 2024, 14(24), 2032; https://doi.org/10.3390/nano14242032 - 18 Dec 2024

Cited by 3 | Viewed by 1452

Abstract

Bi₂O₃ particles are introduced as foreign additives onto SnO₂ nanoparticles (NPs) surfaces for the efficient detection of oxygenated volatile organic compounds (VOCs). Bi₂O₃-loaded SnO₂ materials are prepared via the impregnation method followed by calcination [...] Read more.

Bi₂O₃ particles are introduced as foreign additives onto SnO₂ nanoparticles (NPs) surfaces for the efficient detection of oxygenated volatile organic compounds (VOCs). Bi₂O₃-loaded SnO₂ materials are prepared via the impregnation method followed by calcination treatment. The abundant Bi₂O₃/SnO₂ interfaces are constructed by the uniform dispersion of Bi₂O₃ particles on the SnO₂ surface. The results of oxygen temperature-programmed desorption suggest that Bi₂O₃-loaded SnO₂ samples display improved surface oxygen ions than neat-SnO₂ NPs. As a result, the gas sensor based on 1 mol% Bi₂O₃-loaded SnO₂ (1Bi-L-SnO₂) composites shows significantly higher sensitivity and a faster response speed toward various oxygenated VOCs compared with SnO₂, especially at 200 °C and 250 °C. The results of catalytic combustion and temperature-programmed reaction measurements reveal the dominant role of adsorption and partial oxidation during ethanol combustion on SnO₂ and 1Bi-L-SnO₂ surfaces. In this case, the improvement in the sensing performance of the 1Bi-L-SnO₂ sensor can be associated with the increase in surface oxygen ions at Bi₂O₃/SnO₂ interfaces. The results confirm the significant role of surface functionalization for sensing materials. The obtained outstanding sensing performance provides the potential application for the simultaneous detection of total oxygenated VOCs in practice. Full article

(This article belongs to the Special Issue Nanostructured Materials in Gas Sensing Applications)

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14 pages, 2397 KB

Open AccessEditor’s ChoiceArticle

Controllable Growth of Monolayer and Bilayer WSe₂ by Liquid-Phase Precursor via Chemical Vapor Deposition for Photodetection

by Siyuan Wang, Pinyi Wang, Hailun Tang, Shilong Yu, Huihui Ye, Xinyu Fang, Jing Ding, Yang Yang and Hai Li

Nanomaterials 2024, 14(24), 2021; https://doi.org/10.3390/nano14242021 - 16 Dec 2024

Cited by 2 | Viewed by 1843

Abstract

Two-dimensional WSe₂ nanosheets have received increasing attention due to their excellent optoelectronic properties. Solid precursors, such as WO₃ and Se powders, have been extensively employed to grow WSe₂ nanosheets by the chemical vapor deposition (CVD) method. However, the high melting [...] Read more.

Two-dimensional WSe₂ nanosheets have received increasing attention due to their excellent optoelectronic properties. Solid precursors, such as WO₃ and Se powders, have been extensively employed to grow WSe₂ nanosheets by the chemical vapor deposition (CVD) method. However, the high melting point of WO₃ results in heterogeneous nucleation sites and nonuniform growth of the WSe₂ nanosheet. By dissolving WO₃ powder in a NaOH solution, we report a facile and uniform growth of monolayer and bilayer WSe₂ nanosheets on a SiO₂/Si substrate at a large scale using liquid precursor by the CVD method. The size and thickness of the WSe₂ nanosheets were controlled by modulating the precursor concentration and growth temperature. The as-prepared monolayer and bilayer WSe₂ nanosheets were well characterized by optical microscopy, atomic force microscopy, and Raman and photoluminescence spectroscopy. With the increase in precursor concentration, the size of the monolayer WSe₂ increased up to 120 μm. Bilayer WSe₂ nanosheets were grown at higher temperatures. The photosensitivity of the bilayer WSe₂ was one order of magnitude higher than that of the monolayer WSe₂. The carrier mobility, specific detectivity, photoresponsivity, and external quantum efficiency of the bilayer WSe₂ were about two orders of magnitude higher than those of the monolayer WSe₂. Our method opens up a new avenue to grow monolayer and bilayer WSe₂ for optoelectronic applications. Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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15 pages, 5399 KB

Open AccessEditor’s ChoiceArticle

Studies on Morphological Evolution of Gravure-Printed ZnO Thin Films Induced by Low-Temperature Vapor Post-Treatment

by Giuliano Sico, Vincenzo Guarino, Carmela Borriello and Maria Montanino

Nanomaterials 2024, 14(24), 2006; https://doi.org/10.3390/nano14242006 - 13 Dec 2024

Viewed by 1535

Abstract

In recent years, the morphology control of semiconductor nanomaterials has been attracting increasing attention toward maximizing their functional properties and reaching their end use in real-world devices. However, the development of easy and cost-effective methods for preparing large-scale patterned semiconductor structures on flexible [...] Read more.

In recent years, the morphology control of semiconductor nanomaterials has been attracting increasing attention toward maximizing their functional properties and reaching their end use in real-world devices. However, the development of easy and cost-effective methods for preparing large-scale patterned semiconductor structures on flexible temperature-sensitive substrates remains ever in demand. In this study, vapor post-treatment (VPT) is investigated as a potential, simple and low-cost post-preparative method to morphologically modify gravure-printed zinc oxide (ZnO) nanoparticulate thin films at low temperatures. Exposing nanoparticles (NPs) to acidic vapor solution, spontaneous restructuring pathways are observed as a consequence of NPs tending to reduce their high interfacial energy. Depending on the imposed environmental conditions during the treatment (e.g., temperature, vapor composition), various ZnO thin-film morphologies are produced, from dense to porous ones, as a result of the activation and interplay of different spontaneous interface elimination mechanisms, including dissolution–precipitation, grain boundary migration and grain rotation–coalescence. The influence of VPT on structural/optical properties has been examined via XRD, UV–visible and photoluminescence measurements. Controlling NP junctions and network nanoporosity, VPT appears as promising cost-effective, low-temperature and pressureless post-preparative platform for preparing supported ZnO NP-based films with improved connectivity and mechanical stability, favoring their practical use and integration in flexible devices. Full article

(This article belongs to the Section Physical Chemistry at Nanoscale)

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13 pages, 1050 KB

Open AccessEditor’s ChoiceArticle

Exploring Gluconamide-Modified Silica Nanoparticles of Different Sizes as Effective Carriers for Antimicrobial Photodynamic Therapy

by Ruth Prieto-Montero, Lucia Herrera, Maite Tejón, Andrea Albaya, Jose Luis Chiara, Mónica L. Fanarraga and Virginia Martínez-Martínez

Nanomaterials 2024, 14(24), 1982; https://doi.org/10.3390/nano14241982 - 11 Dec 2024

Viewed by 1578

Abstract

Antimicrobial resistance (AMR), a consequence of the ability of microorganisms, especially bacteria, to develop resistance against conventional antibiotics, hampering the treatment of common infections, is recognized as one of the most imperative health threats of this century. Antibacterial photodynamic therapy (aPDT) has emerged [...] Read more.

Antimicrobial resistance (AMR), a consequence of the ability of microorganisms, especially bacteria, to develop resistance against conventional antibiotics, hampering the treatment of common infections, is recognized as one of the most imperative health threats of this century. Antibacterial photodynamic therapy (aPDT) has emerged as a promising alternative strategy, utilizing photosensitizers activated by light to generate reactive oxygen species (ROS) that kill pathogens without inducing resistance. In this work, we synthesized silica nanoparticles (NPs) of different sizes (20 nm, 80 nm, and 250 nm) functionalized with the photosensitizer Rose Bengal (RB) and a gluconamide ligand, which targets Gram-negative bacteria, to assess their potential in aPDT. Comprehensive characterization, including dynamic light scattering (DLS) and photophysical analysis, confirmed the stability and effective singlet oxygen production of the functionalized nanoparticles. Although the surface loading density of Rose Bengal was constant at the nanoparticle external surface, RB loading (in mg/g nanoparticle) was size-dependent, decreasing with increasing nanoparticle diameter. Further, the spherical geometry of nanoparticles favored smaller nanoparticles for antibacterial PDT, as this maximizes the surface contact area with the bacteria wall, with the smallest (20 nm) and intermediate (80 nm) particles being more promising. Bacterial assays in E. coli revealed minimal dark toxicity and significant light-activated phototoxicity for the RB-loaded nanoparticles. The addition of gluconamide notably enhanced phototoxic activity, particularly in the smallest nanoparticles (RB-G-20@SiNP), which demonstrated the highest phototoxicity-to-cytotoxicity ratio. These findings indicate that small, gluconamide-functionalized silica nanoparticles are highly effective for targeted aPDT, offering a robust strategy to combat AMR. Full article

(This article belongs to the Special Issue Nanotechnology Applied in Modern Photodynamic Therapy)

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13 pages, 10236 KB

Open AccessEditor’s ChoiceArticle

Controlling the Optical and Electrical Properties of Perovskite Films and Enhancing Solar Cell Performance Using the Photonic Curing Process

by Moulay Ahmed Slimani, Arjun Wadhwa, Luis Felipe Gerlein, Jaime A. Benavides-Guerrero, Mohamad Hassan Taherian, Ricardo Izquierdo and Sylvain G. Cloutier

Nanomaterials 2024, 14(23), 1975; https://doi.org/10.3390/nano14231975 - 9 Dec 2024

Cited by 2 | Viewed by 1602

Abstract

The most common method of processing metal oxide and perovskite thin films in the laboratory is thermal annealing (TA), which is a constraint for the commercialization of large-scale perovskite solar cells. Here, we present a photonic curing (PC) process to produce fully photonically [...] Read more.

The most common method of processing metal oxide and perovskite thin films in the laboratory is thermal annealing (TA), which is a constraint for the commercialization of large-scale perovskite solar cells. Here, we present a photonic curing (PC) process to produce fully photonically annealed perovskite cells—a fast process with well-controlled, short light pulses—to develop perovskite photovoltaic devices with high efficiency. We also demonstrate how to use the parameters of the photonic annealing system to control the optical, electrical, morphological, and structural properties of perovskite layers for photovoltaic device applications. The effect of PC treatment on the microstructure, granularity, and electronic properties was studied by scanning electron microscopy (SEM), photoluminescence (PL), and transient photocurrent (TPC). The degree of conversion of the perovskite precursor and its influence on the electronic structure have been identified.

S n O_{2}

and perovskite films were treated with a single pulse and produced PCE comparable to control samples treated by TA. Full article

(This article belongs to the Special Issue Organic/Perovskite Solar Cell)

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14 pages, 3727 KB

Open AccessEditor’s ChoiceArticle

Engineering Zn/Fe Mixed Metal Oxides with Tunable Structural and Magnetic Properties for Magnetic Particle Imaging

by Qianyi Zhang, Bing Sun, Saeed Shanehsazzadeh, Andre Bongers and Zi Gu

Nanomaterials 2024, 14(23), 1964; https://doi.org/10.3390/nano14231964 - 7 Dec 2024

Cited by 2 | Viewed by 1605

Abstract

Engineering magnetic nanoparticles with tunable structural properties and magnetism is critical to develop desirable magnetic particle imaging (MPI) tracers for biomedical applications. Here we present a new superparamagnetic metal oxide nanoparticle with a controllable chemical composition and magnetism for imaging tumor xenografts in [...] Read more.

Engineering magnetic nanoparticles with tunable structural properties and magnetism is critical to develop desirable magnetic particle imaging (MPI) tracers for biomedical applications. Here we present a new superparamagnetic metal oxide nanoparticle with a controllable chemical composition and magnetism for imaging tumor xenografts in living mice. Superparamagnetic Zn/Fe mixed metal oxide (ZnFe-MMO) nanoparticles are fabricated via a facile one-pot co-precipitation method in water followed by thermal decomposition with tunable Zn/Fe ratios and at various calcination temperatures. This work, for the first time, presented LDH-derived metal oxides for an MPI application. The metal composition is tunable to present an optimized MPI performance. The analytical results demonstrate that ZnFe-MMO nanoparticles at the designed molar ratio of Zn/Fe = 2:1 after 650 °C calcination demonstrate a higher saturation magnetization (M_S) value and optimal MPI signal than the samples presented with other conditions. The excellent biocompatibility of ZnFe-MMO is demonstrated in both breast cancer cells and fibroblast cell cultures. In vivo imaging of 4T1 tumor xenografts in mice using ZnFe-MMO as a tracer showed that the mean signal intensity is 1.27-fold higher than the commercial tracer VivoTrax at 72 h post-injection, indicating ZnFe-MMO’s promise for prolonged MPI imaging applications. Full article

(This article belongs to the Collection Magnetic Nanostructured Materials: Synthesis, Characterization and Their Cutting-Edge Applications)

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22 pages, 2685 KB

Open AccessEditor’s ChoiceReview

Recent Advances in DNA Origami-Enabled Optical Biosensors for Multi-Scenario Application

by Ziao Hao, Lijun Kong, Longfei Ruan and Zhengtao Deng

Nanomaterials 2024, 14(23), 1968; https://doi.org/10.3390/nano14231968 - 7 Dec 2024

Cited by 2 | Viewed by 3451

Abstract

Over the past few years, significant progress has been made in DNA origami technology due to the unrivaled self-assembly properties of DNA molecules. As a highly programmable, addressable, and biocompatible nanomaterial, DNA origami has found widespread applications in biomedicine, such as cell scaffold [...] Read more.

Over the past few years, significant progress has been made in DNA origami technology due to the unrivaled self-assembly properties of DNA molecules. As a highly programmable, addressable, and biocompatible nanomaterial, DNA origami has found widespread applications in biomedicine, such as cell scaffold construction, antimicrobial drug delivery, and supramolecular enzyme assembly. To expand the scope of DNA origami application scenarios, researchers have developed DNA origami structures capable of actively identifying and quantitatively reporting targets. Optical DNA origami biosensors are promising due to their fast-to-use, sensitive, and easy implementation. However, the conversion of DNA origami to optical biosensors is still in its infancy stage, and related strategies have not been systematically summarized, increasing the difficulty of guiding subsequent researchers. Therefore, this review focuses on the universal strategies that endow DNA origami with dynamic responsiveness from both de novo design and current DNA origami modification. Various applications of DNA origami biosensors are also discussed. Additionally, we highlight the advantages of DNA origami biosensors, which offer a single-molecule resolution and high signal-to-noise ratio as an alternative to traditional analytical techniques. We believe that over the next decade, researchers will continue to transform DNA origami into optical biosensors and explore their infinite possible uses. Full article

(This article belongs to the Section Biology and Medicines)

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25 pages, 6294 KB

Open AccessEditor’s ChoiceArticle

Transition to Metallic and Superconducting States Induced by Thermal or Electrical Deoxidation of the Dislocation Network in the Surface Region of SrTiO₃

by Krzysztof Szot, Christian Rodenbücher, Krzysztof Rogacki, Gustav Bihlmayer, Wolfgang Speier, Krystian Roleder, Franciszek Krok, Hugo Keller, Arndt Simon and Annette Bussmann-Holder

Nanomaterials 2024, 14(23), 1944; https://doi.org/10.3390/nano14231944 - 4 Dec 2024

Viewed by 1450

Abstract

The question as to why deoxidized SrTiO_3−δ becomes metallic and superconducting at extremely low levels of oxygen vacancy concentration has been a mystery for many decades. Here, we show that the real amount of effused oxygen during thermal reduction, which is needed [...] Read more.

The question as to why deoxidized SrTiO_3−δ becomes metallic and superconducting at extremely low levels of oxygen vacancy concentration has been a mystery for many decades. Here, we show that the real amount of effused oxygen during thermal reduction, which is needed to induce superconducting properties, is in the range of only 10¹⁴/cm³ and thus even lower than the critical carrier concentrations assumed previously (10¹⁷–10¹⁹/cm³). By performing detailed investigations of the optical and electrical properties down to the nanoscale, we reveal that filaments are forming during reduction along a network of dislocations in the surface layer. Hence, a reduced epi-polished SrTiO_3−δ crystal has to be regarded as a nano-composite consisting of a perfect dielectric matrix with negligible carrier density, which is short-circuited by metallic filaments with a local carrier density in the range of 10²⁰/cm³. We present that electro-degradation leads to a more pronounced evolution of filamentary bundles and thus can generate a superconducting state with higher T_C than thermal reduction. These findings indicate that traditional homogeneous models of superconductivity in self-doped SrTiO_3−δ need to be revised, and we propose an alternative explanation taking into account the coexistence of metallic dislocation cores with polar insulating regions allowing for polaronic coupling. Full article

(This article belongs to the Special Issue Recent Advances in Nanowires and Superconductors (Second Edition))

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17 pages, 9772 KB

Open AccessEditor’s ChoiceReview

Advances and Challenges in Tracking Interactions Between Plants and Metal-Based Nanoparticles

by Kena Zhang, Qingmeng Liu, Yukun Wang, Xigui Liu, Xiaoxia Zhou and Bing Yan

Nanomaterials 2024, 14(23), 1939; https://doi.org/10.3390/nano14231939 - 3 Dec 2024

Cited by 3 | Viewed by 1620

Abstract

Metal-based nanoparticles (MNPs) are increasingly prevalent in the environment due to both natural processes and human activities, leading to direct interactions with plants through soil, water, and air exposure that can have beneficial and detrimental effects on plant growth and health. Understanding the [...] Read more.

Metal-based nanoparticles (MNPs) are increasingly prevalent in the environment due to both natural processes and human activities, leading to direct interactions with plants through soil, water, and air exposure that can have beneficial and detrimental effects on plant growth and health. Understanding the uptake, translocation, and transformation of MNPs in plants is crucial for assessing environmental risks and leveraging nanotechnology in agriculture. However, accurate analysis of MNPs in plant tissues poses significant challenges due to complex plant matrices and the dynamic nature of nanoparticles. This short review summarizes recent advances in analytical methods for determining MNP–plant interactions, focusing on pre-processing and quantitative nanoparticle analysis. It highlights the importance of selecting appropriate extraction and analytical techniques to preserve nanoparticle integrity and accurate quantification. Additionally, recent advances in mass spectrometry, microscopy, and other spectroscopic techniques that improve the characterization of MNPs within plant systems are discussed. Future perspectives highlight the need to develop real-time in situ monitoring techniques and sensitive tools for characterizing nanoparticle biotransformation. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

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14 pages, 2662 KB

Open AccessEditor’s ChoiceArticle

Tribological and Heat Transfer Investigation of Graphene Oxide Coatings on Nylon Rotating Bands in an Artillery System

by Hongbin Chen, Zeyang Meng and Shuang Yi

Nanomaterials 2024, 14(23), 1943; https://doi.org/10.3390/nano14231943 - 3 Dec 2024

Cited by 3 | Viewed by 1211

Abstract

Exploring ways to improve the performance of rotating bands is of great importance for enhancing the power of modern artillery. This study prepared graphene oxide-coated Nylon (GO-Nylon) and Nylon samples based on nylon rotating bands in artillery systems to investigate the feasibility of [...] Read more.

Exploring ways to improve the performance of rotating bands is of great importance for enhancing the power of modern artillery. This study prepared graphene oxide-coated Nylon (GO-Nylon) and Nylon samples based on nylon rotating bands in artillery systems to investigate the feasibility of introducing GO-coated nylon rotating band materials to enhance their tribological and thermal properties. The friction behavior and thermal effects of these two surfaces were analyzed under different external loads and surface roughness conditions. The results show that the excellent thermal conductivity of GO effectively reduced temperature accumulation during friction. Under an external load of 8 N, the surface temperature of GO-Nylon decreased by 14% compared to the Nylon surface, and the coefficient of friction (COF) decreased by 21%. At the same time, a simulation model was established, and its calculation results were consistent with the experimental trends, providing a further explanation of the experimental phenomena. This research provides a basis for the application of graphene-based coatings in the defense industry and presents new ideas for the development of high-performance rotating band materials. Full article

(This article belongs to the Special Issue Advances in Nano-Engineered Composite Materials for Thermal Management)

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8 pages, 1914 KB

Open AccessEditor’s ChoiceArticle

A Reconfigurable Polarimetric Photodetector Based on the MoS₂/PdSe₂ Heterostructure with a Charge-Trap Gate Stack

by Xin Huang, Qinghu Bai, Yang Guo, Qijie Liang, Tengzhang Liu, Wugang Liao, Aizi Jin, Baogang Quan, Haifang Yang, Baoli Liu and Changzhi Gu

Nanomaterials 2024, 14(23), 1936; https://doi.org/10.3390/nano14231936 - 1 Dec 2024

Cited by 2 | Viewed by 1787

Abstract

Besides the intensity and wavelength, the ability to analyze the optical polarization of detected light can provide a new degree of freedom for numerous applications, such as object recognition, biomedical applications, environmental monitoring, and remote sensing imaging. However, conventional filter-integrated polarimetric sensing systems [...] Read more.

Besides the intensity and wavelength, the ability to analyze the optical polarization of detected light can provide a new degree of freedom for numerous applications, such as object recognition, biomedical applications, environmental monitoring, and remote sensing imaging. However, conventional filter-integrated polarimetric sensing systems require complex optical components and a complicated fabrication process, severely limiting their on-chip miniaturization and functionalities. Herein, the reconfigurable polarimetric photodetection with photovoltaic mode is developed based on a few-layer MoS₂/PdSe₂ heterostructure channel and a charge-trap structure composed of Al₂O₃/HfO₂/Al₂O₃ (AHA)-stacked dielectrics. Because of the remarkable charge-trapping ability of carriers in the AHA stack, the MoS₂/PdSe₂ channel exhibits a high program/erase current ratio of 10⁵ and a memory window exceeding 20 V. Moreover, the photovoltaic mode of the MoS₂/PdSe₂ Schottky diode can be operated and manipulable, resulting in high and distinct responsivities in the visible broadband. Interestingly, the linear polarization of the device can be modulated under program/erase states, enabling the reconfigurable capability of linearly polarized photodetection. This study demonstrates a new prototype heterostructure-based photodetector with the capability of both tunable responsivity and linear polarization, demonstrating great potential application toward reconfigurable photosensing and polarization-resolved imaging applications. Full article

(This article belongs to the Special Issue 2D Materials for Advanced Sensors: Fabrication and Applications)

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10 pages, 2457 KB

Open AccessEditor’s ChoiceArticle

Angle-Controlled Nanospectrum Switching from Lorentzian to Fano Lineshapes

by Fu Tang, Qinyang Zhong, Xiaoqiuyan Zhang, Yuxuan Zhuang, Tianyu Zhang, Xingxing Xu and Min Hu

Nanomaterials 2024, 14(23), 1932; https://doi.org/10.3390/nano14231932 - 30 Nov 2024

Viewed by 1091

Abstract

The tunability of spectral lineshapes, ranging from Lorentzian to Fano profiles, is essential for advancing nanoscale photonic technologies. Conventional far-field techniques are insufficient for studying nanoscale phenomena, particularly within the terahertz (THz) range. In this work, we use a U-shaped resonant ring on [...] Read more.

The tunability of spectral lineshapes, ranging from Lorentzian to Fano profiles, is essential for advancing nanoscale photonic technologies. Conventional far-field techniques are insufficient for studying nanoscale phenomena, particularly within the terahertz (THz) range. In this work, we use a U-shaped resonant ring on a waveguide substrate to achieve precise modulation of Lorentzian, Fano, and antiresonance profiles. THz scattering scanning near-field optical microscopy (s-SNOM) reveals the underlying physical mechanism of these transitions, driven by time-domain phase shifts between the background excitation from the waveguide and the resonance of the U-shaped ring. Our approach reveals a pronounced asymmetry in the near-field response, which remains undetectable in far-field systems. The ability to control spectral lineshapes at the nanoscale presents promising applications in characterizing composite nanoresonators and developing nanoscale phase sensors. Full article

(This article belongs to the Special Issue Light−Matter Interactions Enabled by THz Low-Dimensional Nanophotonic Structures)

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16 pages, 5468 KB

Open AccessEditor’s ChoiceArticle

Enhancing Methylene Blue Adsorption Performance of Ti₃C₂T_x@Sodium Alginate Foam Through Pore Structure Regulation

by Yi Hu, Hongwei Wang, Xianliang Ren, Fang Wu, Gaobin Liu, Shufang Zhang, Haijun Luo and Liang Fang

Nanomaterials 2024, 14(23), 1925; https://doi.org/10.3390/nano14231925 - 29 Nov 2024

Cited by 4 | Viewed by 1572

Abstract

Pore structural regulation is expected to be a facile way to enhance the adsorption performance of MXene. In this work, spherical foam composites consisting of Ti₃C₂T_x and sodium alginate (SA) were synthesized via a vacuum freeze-drying technique. By [...] Read more.

Pore structural regulation is expected to be a facile way to enhance the adsorption performance of MXene. In this work, spherical foam composites consisting of Ti₃C₂T_x and sodium alginate (SA) were synthesized via a vacuum freeze-drying technique. By varying the solution volume of Ti₃C₂T_x, four distinct Ti₃C₂T_x@SA spherical foams with honeycomb-like and lamellar structures with a pore diameter in the range of 100–300 μm were fabricated. Their methylene blue (MB) adsorption performances were then systematically compared. The results revealed that the honeycomb-like porous-structured spherical foams have a significantly higher adsorption capacity than their lamellar counterparts. Notably, the Ti₃C₂T_x@SA honeycomb-like porous foam exhibited a remarkable maximum adsorption capacity (q_m) of 969 mg/g, positioning it at the forefront of MB adsorbent materials. Respective analysis of the adsorption kinetics, thermodynamics, and isotherm model indicated that this MB adsorption of Ti₃C₂T_x@SA honeycomb-like porous foam is characterized to be a physical, endothermic, and monolayer adsorption. The Ti₃C₂T_x@SA honeycomb-like porous foam also demonstrated excellent resistance to ion interference and good reusability, further attesting to its substantial potential for practical applications. X-ray photoelectron spectroscopy (XPS) analysis was employed to elucidate the adsorption mechanism, which was found to involve the synergistic effect of electrostatic adsorption and amidation reaction. This work not only offers new avenues for the development of high-performance adsorption materials but also provides crucial insights into the structural design and performance optimization of porous materials. Full article

(This article belongs to the Special Issue Advanced Porous Nanomaterials: Synthesis, Properties, and Application (Second Edition))

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26 pages, 11335 KB

Open AccessEditor’s ChoiceArticle

Water–Gas Shift over Pt Nanoparticles Dispersed on CeO₂ and Gadolinium-Doped Ceria (GDC) Supports with Specific Nano-Configurations

by Athanasios Androulakis, Ersi Nikolaraki, Catherine Drosou, Kalliopi Maria Papazisi, Stella Balomenou, Dimitrios Tsiplakides, Konstantinos G. Froudas, Pantelis N. Trikalitis, Dimitrios P. Gournis, Paraskevi Panagiotopoulou and Ioannis V. Yentekakis

Nanomaterials 2024, 14(23), 1928; https://doi.org/10.3390/nano14231928 - 29 Nov 2024

Cited by 1 | Viewed by 2001

Abstract

The water–gas shift (WGS) reaction is one of the most significant reactions in hydrogen technology since it can be used directly to produce hydrogen from the reaction of CO and water; it is also a side reaction taking place in the hydrocarbon reforming [...] Read more.

The water–gas shift (WGS) reaction is one of the most significant reactions in hydrogen technology since it can be used directly to produce hydrogen from the reaction of CO and water; it is also a side reaction taking place in the hydrocarbon reforming processes, determining their selectivity towards H₂ production. The development of highly active WGS catalysts, especially at temperatures below ~450 °C, where the reaction is thermodynamically favored but kinetically limited, remains a challenge. From a fundamental point of view, the reaction mechanism is still unclear. Since specific nanoshapes of CeO₂-based supports have recently been shown to play an important role in the performance of metal nanoparticles dispersed on their surface, in this study, a comparative study of the WGS is conducted on Pt nanoparticles dispersed (with low loading, 0.5 wt.% Pt) on CeO₂ and gadolinium-doped ceria (GDC) supports of different nano-morphologies, i.e., nanorods (NRs) and irregularly faceted particle (IRFP) CeO₂ and GDC, produced by employing hydrothermal and (co-)precipitation synthesis methods, respectively. The results showed that the support’s shape strongly affected its physicochemical properties and in turn the WGS performance of the dispersed Pt nanoparticles. Nanorod-shaped CeO_2,NRs and GDC_NRs supports presented a higher specific surface area, lower primary crystallite size and enhanced reducibility at lower temperatures compared to the corresponding irregular faceted CeO_2,IRFP and GDC_IRFP supports, leading to up to 5-fold higher WGS activity of the Pt particles supported on them. The Pt/GDC_NRs catalyst outperformed all other catalysts and exhibited excellent time-on-stream (TOS) stability. A variety of techniques, namely N₂ physical adsorption–desorption (the BET method), scanning and transmission electron microscopies (SEM and TEM), powder X-ray diffraction (PXRD) and hydrogen temperature programmed reduction (H₂-TPR), were used to identify the texture, structure, morphology and other physical properties of the materials, which together with the in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and detailed kinetic studies helped to decipher their catalytic behavior. The enhanced metal–support interactions of Pt nanoparticles with the nanorod-shaped CeO_2,NRs and GDC_NRs supports due to the creation of more active sites at the metal–support interface, leading to significantly improved reducibility of these catalysts, were concluded to be the critical factor for their superior WGS activity. Both the redox and associative reaction mechanisms proposed for WGS in the literature were found to contribute to the reaction pathway. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

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8 pages, 3953 KB

Open AccessEditor’s ChoiceArticle

Oblique Deposited Ultra-Thin Silver Films on Polymer Gratings for Sensitive SERS Performance

by Yi-Jun Jen and Meng-Jie Lin

Nanomaterials 2024, 14(23), 1871; https://doi.org/10.3390/nano14231871 - 22 Nov 2024

Viewed by 1009

Abstract

A small amount of silver was obliquely deposited onto a polymer subwavelength grating to form a metasurface that comprised silver split-tubes. An ultra-thin silver film with a monitor-controlled thickness of 20 nm at the corner of each ridge of the grating provided the [...] Read more.

A small amount of silver was obliquely deposited onto a polymer subwavelength grating to form a metasurface that comprised silver split-tubes. An ultra-thin silver film with a monitor-controlled thickness of 20 nm at the corner of each ridge of the grating provided the most sensitive surface-enhanced Raman scattering (SERS) measurements. An excitation laser beam that was incident from the substrate provided similar or better SERS enhancement than did the general configuration with the laser beam incident directly on the surface of the nanostructure. Near-field simulations were conducted to model the localized electric field enhancement and to quantify the SERS performance, demonstrating the effectiveness of this novel deposition method. Full article

(This article belongs to the Special Issue Advances and Innovations in Glancing Angle Deposition and Related Nanostructures)

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13 pages, 3209 KB

Open AccessEditor’s ChoiceArticle

Permanent Strain Engineering of Molybdenum Disulfide Using Laser-Driven Stressors for Energy-Efficient Resistive Switching Memory Devices

by Heeyoon Jang, Seok-Ki Hyeong, Byeongjin Park, Tae-Wook Kim, Sukang Bae, Sung Kyu Jang, Yonghun Kim and Seoung-Ki Lee

Nanomaterials 2024, 14(23), 1872; https://doi.org/10.3390/nano14231872 - 22 Nov 2024

Viewed by 1503

Abstract

Strain engineering provides an attractive approach to enhance device performance by modulating the intrinsic electrical properties of materials. This is especially applicable to 2D materials, which exhibit high sensitivity to mechanical stress. However, conventional methods, such as using polymer substrates, to apply strain [...] Read more.

Strain engineering provides an attractive approach to enhance device performance by modulating the intrinsic electrical properties of materials. This is especially applicable to 2D materials, which exhibit high sensitivity to mechanical stress. However, conventional methods, such as using polymer substrates, to apply strain have limitations in that the strain is temporary and global. Here, we introduce a novel approach to induce permanent localized strain by fabricating a stressor on SiO₂/Si substrates using fiber laser irradiation, thereby enabling precise control of the surface topography. MoS₂ is transferred onto this stressor, which results in the application of ~0.8% tensile strain. To assess the impact of the internal strain on the operation of ReRAM devices, the flat-MoS₂-based and the strained-MoS₂-based devices are compared. Both devices demonstrate forming-free, bipolar, and non-volatile switching characteristics. The strained devices exhibit a 30% reduction in the operating voltage, which can be attributed to bandgap narrowing and enhanced carrier mobility. Furthermore, the strained devices exhibit nearly a two-fold improvement in endurance, presumably because of the enhanced stability from lattice release effect. These results emphasize the potential of strain engineering for advancing the performance and durability of next-generation memory devices. Full article

(This article belongs to the Special Issue Nanoelectronics: Materials, Devices and Applications (Second Edition))

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16 pages, 4681 KB

Open AccessEditor’s ChoiceArticle

M-Doped (M = Zn, Mn, Ni) Co-MOF-Derived Transition Metal Oxide Nanosheets on Carbon Fibers for Energy Storage Applications

by Andrés González-Banciella, David Martinez-Diaz, Adrián de Hita, María Sánchez and Alejandro Ureña

Nanomaterials 2024, 14(22), 1846; https://doi.org/10.3390/nano14221846 - 19 Nov 2024

Cited by 4 | Viewed by 1813

Abstract

Carbon fiber, with its strong mechanical properties and electrical conductivity, is ideal as a fiber electrode in wearable or structural energy storage devices. However, its energy storage capacity is limited, and coatings like transition metal oxides (TMOs) enhance its electrochemical performance. Metal–organic frameworks [...] Read more.

Carbon fiber, with its strong mechanical properties and electrical conductivity, is ideal as a fiber electrode in wearable or structural energy storage devices. However, its energy storage capacity is limited, and coatings like transition metal oxides (TMOs) enhance its electrochemical performance. Metal–organic frameworks (MOFs) are commonly used to grow TMOs on carbon fibers, increasing the surface area for better energy storage. Despite this, TMOs have limited electrical conductivity, so ion exchange is often used to dope them with additional cations, improving both conductivity and energy storage capacity. This study compares different ion-exchange cations in ZIF-L-derived TMO coatings on carbon fiber. Testing both supercapacitor and Li-ion battery applications, Ni-doped samples showed superior results, attributed to their higher exchange ratio with cobalt. As a supercapacitor electrode, the Ni-doped material achieved 13.3 F/g at 50 mA/g—66% higher than undoped samples. For Li-ion battery anodes, it reached a specific capacity of 410.5 mAh/g at 25 mA/g, outperforming undoped samples by 21.4%. Full article

(This article belongs to the Special Issue Metal Organic Framework (MOF)-Based Micro/Nanoscale Materials)

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21 pages, 2882 KB

Open AccessEditor’s ChoiceReview

Gold Nanoprobes for Robust Colorimetric Detection of Nucleic Acid Sequences Related to Disease Diagnostics

by Maria Enea, Andreia Leite, Ricardo Franco and Eulália Pereira

Nanomaterials 2024, 14(22), 1833; https://doi.org/10.3390/nano14221833 - 16 Nov 2024

Cited by 5 | Viewed by 2835

Abstract

Gold nanoparticles (AuNPs) are highly attractive for applications in the field of biosensing, particularly for colorimetric nucleic acid detection. Their unique optical properties, which are highly sensitive to changes in their environment, make them ideal candidates for developing simple, rapid, and cost-effective assays. [...] Read more.

Gold nanoparticles (AuNPs) are highly attractive for applications in the field of biosensing, particularly for colorimetric nucleic acid detection. Their unique optical properties, which are highly sensitive to changes in their environment, make them ideal candidates for developing simple, rapid, and cost-effective assays. When functionalized with oligonucleotides (Au-nanoprobes), they can undergo aggregation or dispersion in the presence of complementary sequences, leading to distinct color changes that serve as a visual signal for detection. Aggregation-based assays offer significant advantages over other homogeneous assays, such as fluorescence-based methods, namely, label-free protocols, rapid interactions in homogeneous solutions, and detection by the naked eye or using low-cost instruments. Despite promising results, the application of Au-nanoprobe-based colorimetric assays in complex biological matrices faces several challenges. The most significant are related to the colloidal stability and oligonucleotide functionalization of the Au-nanoprobes but also to the mode of detection. The type of functionalization method, type of spacer, the oligo–AuNPs ratio, changes in pH, temperature, or ionic strength influence the Au-nanoprobe colloidal stability and thus the performance of the assay. This review elucidates characteristics of the Au-nanoprobes that are determined for colorimetric gold nanoparticles (AuNPs)-based nucleic acid detection, and how they influence the sensitivity and specificity of the colorimetric assay. These characteristics of the assay are fundamental to developing low-cost, robust biomedical sensors that perform effectively in biological fluids. Full article

(This article belongs to the Special Issue Noble Metal-Based Nanostructures: Optical Properties and Applications)

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15 pages, 5249 KB

Open AccessEditor’s ChoiceArticle

A Comprehensive Microstructure-Aware Electromigration Modeling Framework; Investigation of the Impact of Trench Dimensions in Damascene Copper Interconnects

by Ahmed Sobhi Saleh, Kristof Croes, Hajdin Ceric, Ingrid De Wolf and Houman Zahedmanesh

Nanomaterials 2024, 14(22), 1834; https://doi.org/10.3390/nano14221834 - 16 Nov 2024

Cited by 5 | Viewed by 1408

Abstract

As electronic devices continue to shrink in size and increase in complexity, the current densities in interconnects drastically increase, intensifying the effects of electromigration (EM). This renders the understanding of EM crucial, due to its significant implications for device reliability and longevity. This [...] Read more.

As electronic devices continue to shrink in size and increase in complexity, the current densities in interconnects drastically increase, intensifying the effects of electromigration (EM). This renders the understanding of EM crucial, due to its significant implications for device reliability and longevity. This paper presents a comprehensive simulation framework for the investigation of EM in nano-interconnects, with a primary focus on unravelling the influential role of microstructure, by considering the impact of diffusion heterogeneity through the metal texture and interfaces. As such, the resulting atomic flux and stress distribution within nano-interconnects could be investigated. To this end, a novel approach to generate microstructures of the conductor metal is presented, whereby a predefined statistical distribution of grain sizes obtained from experimental texture analyses can be incorporated into the presented model, making the model predictive under various scales and working conditions with no need for continuous calibration. Additionally, the study advances beyond the state-of-the-art by comprehensively simulating all stages of electromigration including stress evolution, void nucleation, and void dynamics. The model was employed to study the impact of trench dimensions on the dual damascene copper texture and its impact on electromigration aging, where the model findings were corroborated by comparing them to the available experimental findings. A nearly linear increase in normalized time to nucleation was detected as the interconnect became wider with a fixed height for aspect ratios beyond 1. However, a saturation was detected with a further increase in width for lines of aspect ratios below 1, with no effective enhancement in time to nucleation. An aspect ratio of 1 seems to maximize the EM lifetime for a fixed cross-sectional area by fostering a bamboo-like structure, where about a 2-fold of increase was estimated when going from aspect ratio 2 to 1. Full article

(This article belongs to the Special Issue Mechanical and Thermal Properties of Nanomaterials)

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34 pages, 4568 KB

Open AccessEditor’s ChoiceReview

Nanothermodynamics: There’s Plenty of Room on the Inside

by Ralph V. Chamberlin and Stuart M. Lindsay

Nanomaterials 2024, 14(22), 1828; https://doi.org/10.3390/nano14221828 - 15 Nov 2024

Cited by 2 | Viewed by 1599

Abstract

Nanothermodynamics provides the theoretical foundation for understanding stable distributions of statistically independent subsystems inside larger systems. In this review, it is emphasized that extending ideas from nanothermodynamics to simplistic models improves agreement with the measured properties of many materials. Examples include non-classical critical [...] Read more.

Nanothermodynamics provides the theoretical foundation for understanding stable distributions of statistically independent subsystems inside larger systems. In this review, it is emphasized that extending ideas from nanothermodynamics to simplistic models improves agreement with the measured properties of many materials. Examples include non-classical critical scaling near ferromagnetic transitions, thermal and dynamic behavior near liquid–glass transitions, and the 1/f-like noise in metal films and qubits. A key feature in several models is to allow separate time steps for distinct conservation laws: one type of step conserves energy and the other conserves momentum (e.g., dipole alignment). This “orthogonal dynamics” explains how the relaxation of a single parameter can exhibit multiple responses such as primary, secondary, and microscopic peaks in the dielectric loss of supercooled liquids, and the crossover in thermal fluctuations from Johnson–Nyquist (white) noise at high frequencies to 1/f-like noise at low frequencies. Nanothermodynamics also provides new insight into three basic questions. First, it gives a novel solution to Gibbs’ paradox for the entropy of the semi-classical ideal gas. Second, it yields the stable equilibrium of Ising’s original model for finite-sized chains of interacting binary degrees of freedom (“spins”). Third, it confronts Loschmidt’s paradox for the arrow of time, showing that an intrinsically irreversible step is required for maximum entropy and the second law of thermodynamics, not only in the thermodynamic limit but also in systems as small as

N = 2

particles. Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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21 pages, 5741 KB

Open AccessEditor’s ChoiceArticle

Bimetallic NiCo Nanoparticles Embedded in Organic Group Functionalized Mesoporous Silica for Efficient Hydrogen Production from Ammonia Borane Hydrolysis

by Juti Rani Deka, Diganta Saikia, Ning-Fang Lu, Chieh-Yu Chen, Hsien-Ming Kao and Yung-Chin Yang

Nanomaterials 2024, 14(22), 1818; https://doi.org/10.3390/nano14221818 - 13 Nov 2024

Cited by 1 | Viewed by 1406

Abstract

In this study, bimetallic NiCo nanoparticles (NPs) were encapsulated within the mesopores of carboxylic acid functionalized mesoporous silica (CMS) through the chemical reduction approach. Both NaBH₄ and NH₃BH₃ were used as reducing agents to reduce the metal ions simultaneously. [...] Read more.

In this study, bimetallic NiCo nanoparticles (NPs) were encapsulated within the mesopores of carboxylic acid functionalized mesoporous silica (CMS) through the chemical reduction approach. Both NaBH₄ and NH₃BH₃ were used as reducing agents to reduce the metal ions simultaneously. The resulting composite was used as a catalyst for hydrolysis of ammonia borane (NH₃BH₃, AB) to produce H₂. The bimetallic NiCo NPs supported on carboxylic group functionalized mesoporous silica, referred to as Ni_xCo_100−x@CMS, exhibited significantly higher catalytic activity for AB hydrolysis compared to their monometallic counterparts. The remarkable activity of Ni_xCo_100−x@CMS could be ascribed to the synergistic contributions of Ni and Co, redox reaction during the hydrolysis, and the fine-tuned electronic structure. The catalytic performance of the Ni_xCo_100−x@CMS nanocatalyst was observed to be dependent on the composition of Ni and Co. Among all the compositions investigated, Ni₄₀Co₆₀@CMS demonstrated the highest catalytic activity, with a turn over frequency (TOF) of 18.95 mol_H2min⁻¹mol_catalyst⁻¹ and H₂ production rate of 8.0 L min⁻¹g⁻¹. The activity of Ni₄₀Co₆₀@CMS was approximately three times greater than that of Ni@CMS and about two times that of Co@CMS. The superior activity of Ni₄₀Co₆₀@CMS was attributed to its finely-tuned electronic structure, resulting from the electron transfer of Ni to Co. Furthermore, the nanocatalyst exhibited excellent durability, as the carboxylate group in the support provided a strong metal–support interaction, securely anchoring the NPs within the mesopores, preventing both agglomeration and leakage. Full article

(This article belongs to the Special Issue Applications of Nanoporous Materials in Sensors and Catalysis)

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18 pages, 4647 KB

Open AccessEditor’s ChoiceArticle

Hematological Response to Particle Debris Generated During Wear–Corrosion Processes of CoCr Surfaces Modified with Graphene Oxide and Hyaluronic Acid for Joint Prostheses

by María L. Escudero, Maria C. García-Alonso, Belén Chico, Rosa M. Lozano, Luna Sánchez-López, Manuel Flores-Sáenz, Soledad Cristóbal-Aguado, Rafael Moreno-Gómez-Toledano and Soledad Aguado-Henche

Nanomaterials 2024, 14(22), 1815; https://doi.org/10.3390/nano14221815 - 13 Nov 2024

Cited by 1 | Viewed by 1298

Abstract

Various surface modifications to increase the lifespan of cobalt–chromium (CoCr) joint prostheses are being studied to reduce the wear rate in bone joint applications. One recently proposed modification involves depositing graphene oxide functionalized with hyaluronic acid (a compound present in joints) on CoCr [...] Read more.

Various surface modifications to increase the lifespan of cobalt–chromium (CoCr) joint prostheses are being studied to reduce the wear rate in bone joint applications. One recently proposed modification involves depositing graphene oxide functionalized with hyaluronic acid (a compound present in joints) on CoCr surfaces, which can act as a solid lubricant. This paper analyzes the biological alterations caused by wear–corrosion phenomena that occur in joints, both from the perspective of the worn surface (in vitro model) and the particles generated during the wear processes (in vivo model). The analysis of the inflammatory response of macrophage was performed on CoCr surfaces modified with graphene oxide and functionalized with hyaluronic acid (CoCr-GO-HA), before and after wear–corrosion processes. The wear particles released during the wear–corrosion tests of the CoCr-GO-HA/CoCr ball pair immersed in 3 g/L hyaluronic acid were intra-articularly injected into the experimental animals. The hematological analysis in vivo was made considering a murine model of intra-articular injection into the left knee in male adult Wistar rats, at increasing concentrations of the collected wear particles dispersed in 0.9% NaCl. Non-significant differences in the inflammatory response to unworn CoCr-GO-HA surfaces and control (polystyrene) were obtained. The wear–corrosion of the CoCr-GO-HA disk increased the inflammatory response at both 72 and 96 h of material exposure compared to the unworn CoCr-GO-HA surfaces, although the differences were not statistically significant. The pro-inflammatory response of the macrophages was reduced on the worn surfaces of the CoCr modified and functionalized with graphene oxide (GO) and hyaluronic acid (HA), compared to the worn surfaces of the unmodified CoCr. The hematological analysis and tissue reactions after intra-articular injection did not reveal pathological damage, with average hematological values recorded, although slight reductions in creatinine and protein within non-pathological ranges were found. Some traces of biomaterial particles in the knee at the highest concentration of injected particles were only found but without inflammatory signs. The results show the potential benefits of using graphene in intra-articular prostheses, which could improve the quality of life for numerous patients. Full article

(This article belongs to the Special Issue Advanced Studies in Bionanomaterials)

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